1. Field of the Invention
This invention relates to compositions for preparing formulated hard-bodied arthropod cadavers, such as, for example, from the family Tenebrionidae such as Tenebrio molitor, containing biological organisms having pesticidal and/or antimicrobial activity; compositions containing formulated hard-bodied arthropod cadavers; and methods for preparing and using formulated arthropod cadavers.
2. Description of the Related Art
Control of pest and/or microbial infestations and the direct loss caused by infestations are costly. Myriad approaches have been pursued to control pests. Various pathogenic biological control agents such as species of nematodes, fungi, bacteria, virus, or protozoa can suppress populations of important pests. These biological control organisms are most often applied in aqueous suspension for control of agricultural pests. Their usage is limited by cost and, or inconsistent levels of efficacy in pest supression following field applications.
Entomopathogenic nematodes are just one example of a biocontrol agent which can be formulated into a carrier to control pests. Entomopathogenic nematodes in the genera Steinernema and Heterorhabditis are obligate parasites of insects which can control a wide variety of economically important pests. These nematodes are commercially applied as infective juveniles in aqueous suspension using various agricultural spray equipment, irrigation systems, or injection techniques (Grewal, Entomopathogenic nematology, Gaugler et al. (Eds), CABI, New York, N.Y., 265-288, 2002; Georgis, Formulation and Application Technology, IN: “Entomopathogenic Nematodes in Biological Control, supra, 173-194, 1990; Koppenhofer, Nematodes, IN: “Field Manual of Techniques in Invertebrate Pathology”, L. A. Lacey and H. K. Kaya, Eds., 283-301, 200, Kluwer Academic Publishers, Dordrecht). Entomopathogenic nematodes generally infect their host by entering natural openings in the host. Heterorhabditids also have the ability to enter certain hosts through the cuticle using a tooth. After entering a host, symbiotic bacteria are released, the nematodes molt, reproduce, and after 1-3 generations, dauer stage juveniles emerge. The dauer juvenile stage is the only stage that is capable of surviving and infecting new hosts in the natural environment. Infective juveniles enter the host and release symbiotic bacteria which aid in (a) killing the host, (b) providing nutrients to the nematodes, and (c) releasing antibiotics, which prevent invasion by other microbes; the bacteria, however, cannot survive outside of the host in a natural environment (e.g. soil) without the nematode (Poiner, Biology and Taxonomy of Steinemematidae and Heterorhabditidae, In: Entomopathogenic Nematodes in Biological Control, R. Gaugler and H. K. Kaya, Eds., 23-62, 1990, CRC Press, Boca Raton, Fla.). The number of nematodes produced per insect varies among nematode species, and within species in different hosts. Heterorhabditis bacteriophora Poinar, for example, can produce over 50,000 infective juveniles per Tenebrio molitar larva (Shaprio-Ilan and Gaugler, Production Technology for Entomopathogenic Nematodes and Their Bacterial Symbionts, J. Ind. Microbiol. & Biotech., Volume 28, 137-146, 2002).
Entomopathogenic nematodes are important biological control agents for a variety of economically important pests in agricultural and urban environments (Grewal and Georgis, Entomophathogenic nematodes, IN: “Methods in Biotechnology”, Volume 5, Biopesticides: Use and Delivery, F. R. Hall and J. J. Menn, Eds., 271-299, 1998, Totowa, N.J., Humana Press, Inc.; Kaya and Gaugler, Entomopathogenic Nematodes, Annu. Rev. Entomol., Volume 38, 181-206, 1993). The nematodes can be mass-produced using in vivo and in vitro methods (Friedman, Commercial production and development, IN: “Entomopathogenic Nematodes in Biological Control”, R. Gaugler and H. K. Kaya, Eds., 153-172, 1990, Boca Raton, Fla., CRC Press; Sharpiro and Gaugler, 2002, supra). More wide-spread use of etnomopathogenic nematodes as biological control agents has been limited by cost competitiveness and inconsistent levels of field efficacy (Shapiro-Ilan et al., Factors Affecting Commercial Success: Case Studies in Cotton, Turf, and Citrus. IN: “Entomopathogenic Nematology”, R. Gaugler, Ed., 333-356, 2002, CABI, New York, N.Y.).
Research indicates that entomopathogenic nematodes may also be applied in infected cadavers [(Creighton and Fasuliotis, Heterorhabditis sp. (Nematoda: Heterorhabditidae): A nematode parasite isolated from the banded cucumber beetle Diabrotica balteata, J. Nematology, Volume 17, 150-153, 1985; Jansson et al., Field efficacy and persistence of entomopathogenic nematodes (Rhabditida: Steinernematidae, Heterorhabditidae) for control of sweet potato weevil (Coleoptera: Apionidae) in Southern Florida, J. Econ. Entomology, Volume 86, 1055-1063, 1993)]. In this approach, nematode-infected cadavers are disseminated and pest suppression is subsequently achieved by the progeny infective juveniles that exit the cadavers. Laboratory studies indicate that nematode application in infected hosts may be superior to application in aqueous suspension (Shapiro and Glazer, Comparison of entomopathogenic nematode dispersal from infected hosts versus aqueous suspension, Environ. Entomol., Volume 25, 1455-1461, 1996; Shapiro and Lewis, Comparison of entomlopathogenic nematode infectivity from infected hosts versus aqueous suspension, Environ Entomol., Volume 28, 907-911, 1999). Indeed, experiments conducted in the greenhouse indicated superior pest suppression when nematodes were applied in infected-insect cadavers compared to aqueous applied nematodes (Shapiro-Ilan et al., Superior Efficacy Observed in Entomopathogenic Nematodes Applied in Infected-Host Cadavers Compared with Application in Aqueous Suspension, J. Invertebr. Pathol., Volume 83, 270-272, 2003). Additionally, for in vivo mass production, application of nematodes in infected cadavers can be less costly than aqueous application because it requires less steps in the process and is thus less costly (Shapiro-Ilan and Gauger, 2002, supra). Furthermore, Koppenhofer (2000, supra) reported that entomopathogenic nematodes can survive dry conditions for extended periods if they remain inside a host cadaver. Commercialization of nematode-infected cadavers has been prevented due to problems in storage and application (Koppenhofer, 2000, supra). Nematode-infected hosts stick together or rupture during transport and/or application, which results in reduced efficacy. Formulating nematode-infected cadavers by coating them can overcome problems of sticking or rupturing, and can provide shelf-life, stability and ease of handling (Shapiro-Ilan et al., U.S. Pat. No. 6,524,061, Feb. 25, 2003; Shapiro-Ilan et al., Formulation of Entomopathogenic Nematode-Infected Cadavers, J. Invertevr. Pathol., Volume 78, 17-23, 2001).
Various formulations for entomopathogenic organisms are known, however there remains a need in the art for nematode formulations which maintain infectivity and reproduction levels for effective biological control that requires the least amount of formulation and enhances the use of biocontrol agents thereby reducing reliance on chemical pesticides. The present invention, as described below, is different from related art nematode cadaver formulations.